Charlie, along with Oscar, promoting a positive attitude (3-2)
I believe the answer is:
can-do
'promoting a positive attitude' is the definition.
I can't judge whether this defines the answer.
'charlie along with oscar' is the wordplay.
'charlie' becomes 'C' (phonetic alphabet).
'along with' becomes 'and' (I've seen this in another clue).
'oscar' becomes 'O' (phonetic alphabet: alpha, bravo, charlie etc.).
'c'+'and'+'o'='CAN-DO'
Can you help me to learn more?
(Other definitions for can-do that I've seen before include "Positive-thinking" , "Showing willingness to get the job done" , "Positive" .)